Very large gas or coal gasification sites may be built in the near future. All gasification processes require large quantities of high pressure oxygen.
Air separation unit (ASU) plant sizes have been growing steadily over the last four decades and there is no sign for the trend to stop. With plant sizes getting larger and larger, liquid back-up issues become impractical or impossible for plant outages lasting for more than a few hours.
Current technologies would allow plant sizes up to 7000 metric tonnes of oxygen per day. Presently, largest reference plant sizes are between 4000 and 5000 metric tonnes per day.
Coal gasification in the near future for example may require very large oxygen consumption reaching as high as 50 000 T/D. Gas-to-liquid GTL plant is another example with high oxygen requirement in the range of 20 000-40 000 T/D. It becomes obvious there is a need for an improved and rational production concept for oxygen in such large facilities.
This invention provides a new approach for building large facilities requiring multiple large trains of oxygen plants. A new concept for cost effective production back-up is also integrated in this new scheme.